© 2011 Pearson Education, Inc. CHAPTER 7 The Use and Restoration of Ecosystems

© 2011 Pearson Education, Inc.

CHAPTER 7

The Use and Restoration of Ecosystems


Introduction to ecosystem restoration• Pacific halibut live in northern parts of the Pacific

Ocean• In bottom waters of the continental shelf• It has supported a commercial fishery since the

1800s• It has been heavily regulated since the 1920s

• The fishing fleet fished until the total allowable catch (TAC) was reached• In 1990, the season lasted only six days

• Intensive fishing caused lost and damaged gear• Endangered the crew and vessels


A new management strategy for halibut• Canada and the U.S. adopted the individual quota

(IQ) management strategy• Owners of vessels were allocated a percentage of

TAC• They decide when to fish within the season

• The number of vessels decreased• Income increased• Fish stocks improved

• This strategy involved the fishing community


Ecosystem capital• Biomes: reflect organism responses to climatic

conditions• Terrestrial biomes: forests and woodlands, grasslands

and savannas, croplands, wetlands, desert lands, and tundra

• Oceanic ecosystems: coastal ocean and bays, coral reefs, open ocean

• Human economy and well-being directly depend on exploitation of natural goods (provisioning services)• Ecosystems provide all food, fuel, wood, fibers, etc.

• Natural services (regulating and cultural services) process energy and circulate matter


Services from various types of ecosystems


Ecosystems perform natural services• Normally functioning ecosystems provide free natural

goods and services• Global ecosystems provide $41 trillion/year

• A functioning mangrove swamp provides $14,450/acre• Storm protection, forest products, spawning grounds

• If converted to a shrimp farm, it provides $3,376/acre• But pollution and land degradation cost $2,200/acre• For a net income of $1,175/acre!

• Benefits of conversion are local, short, and specific• Loss of services is regional, long-term, and diffuse


Shrimp aquaculture farms in Thailand


Ecosystems as natural resources• If natural services are so valuable, why are they

destroyed?• A natural area is protected only when the society

values its services higher than the value assigned to a direct human use of the resource

• Natural resources: natural ecosystems and their biota• Are expected to produce something of value• The most commonly understood value is economic

• Referring to natural systems as resources makes it easy to lose sight of their ecological value• Ecosystem capital avoids this mistake


Valuing ecosystems• Markets assess economic value

• But not the monetary value of ecosystem services• Instrumental value works for provisioning services of

ecosystems (timber, fish, crops)

• Regulating and cultural services (ecological services) are less local and harder to price• They are public goods, essential for human well-being

• Cutting forests provides immediate economic benefits• But has a long-term loss in regulating and support

services


Private vs. public lands• Natural ecosystems are maintained when they

provide the greatest economic (direct-use) value for their owners

• Corporate-owned Maine forests are used for lumber and paper• Land sold to developers would become house lots

• Some ecosystems are publically owned (state, federal lands) or cannot be owned (oceans)• They are still exploited

• Sustainable exploitation maintains natural services• Ecosystems can also be restored


Domesticated nature• Humans have dominated most landscapes

• 50% of the land is now used for crop and livestock production

• Half of the world’s forests have been lost

• Domesticated ecosystems still provide services• But at our consent and for our benefit

• As populations increase, so will pressures on ecosystems• Maintaining ecosystem capital will become harder

• The ability of ecosystems to sustain future generations can no longer be taken for granted• 15 of 24 natural services are declining worldwide


Conservation, preservation, restoration• Renewable resource: ecosystem’s and biota’s

ability to regenerate• Ecosystems can replenish themselves

• They are sustainable

• Conservation of biota and ecosystem manages or regulates use so it does not exceed the capacity of the species or system to renew itself• Has a well-defined goal


Preservation is not conservation• Its goal is to ensure species and ecosystem continuity

regardless of their potential utility• May preclude making use of the species or ecosystem

• Old-growth (virgin) forests must be preserved (not cut)• Second-growth forests can be conserved (cut

sustainably)

• Conservation and preservation can conflict• Endangered Muriqui monkeys of Brazil need second-

growth forests• Conservation of forests is essential for preservation of

this monkey


Muriqui monkey


Patterns of human use of natural ecosystems• Consumptive use: people harvest natural resources

for food, shelter, tools, fuel, clothing• Not in a country’s calculated market economy

• People barter or sell goods to meet their own needs

• This “wild income” is important to the world’s poor

• Bush meat: wild game in Africa that provides protein• Largely unregulated and involves poaching

• Contributes to the decline of 30 endangered species

• Commercially killed primate meat is found in New York, London, Paris, etc.


Consumptive use


Productive use• Productive use: the exploitation of ecosystem

resources for economic gain• Products are harvested and sold

• An important source of revenue and employment

• For example, commercial trade in wood products generated $468 billion in 2006• Employing 13.7 million people

• Wild animals and plants provide initial breeding stock• Sources of genes for crop plants or animals

• Sources of new medicines


Productive use


The four types of tenure• Consumptive and productive uses of natural

ecosystem resources are the consequences of the rights of tenure (property rights) over land and water

• Private ownership: restricts access to natural resources

• Commercial ownership: permits use of natural resources by members of the community

• State ownership: implies regulated use• Open access: resources can be used by anyone• Each has the potential for abuse or stewardship


Maximum sustainable yield• The central question in managing a renewable

resource:• How much continual use can be sustained without

undercutting the ability for renewal?

• Maximum sustainable yield (MSY): the highest possible rate of use the system can match with its own rate of replacement or maintenance• MSY applies to harvesting biota, air/water quality, soils• Used in timber cutting, fishing, park visitation, pollution

• MSY is just before the point at which use begins to destroy the system’s regenerative capacity


Optimal populations• Carrying capacity of an ecosystem: the maximum

population the ecosystem can sustainably support• A population below carrying capacity grows

• This yield can be harvested

• In a population approaching carrying capacity, competition between individuals reduces recruitment

• In a population near or at carrying capacity, thinning reduces competition and obtains optimal growth

• MSY is not obtained with a population at the carrying capacity


Maximum sustainable yield


Obtaining MSY is difficult• The optimal population for harvesting at MSY

is halfway to the carrying capacity• Using MSY is complicated

• Carrying capacity and optimal population vary

• Replacement of harvested individuals varies

• Humans adversely affect habitats, carrying capacity, sustainable yields, etc.

• Accurate estimates must be made• Data on population size and recruitment rates are

often hard to obtain


The precautionary principle• MSY is used to set a fixed quota

• In fisheries, it’s the total allowable catch (TAC)

• Inaccurate data overestimate TAC• Fishers and politicians pressure to keep harvests high

• With uncertainties, overuse, and resource depletion, managers turn to the precautionary principle: where there is uncertainty, managers must favor resource protection• Exploitation limits are set below MSY

• Conflicts arise between users and managers


Using the commons• A common-pool resource: owned by many people

• Or by no one (open access)

• Commons: a system with open access• Use by one does not subtract from use by others• Examples: knowledge, federal grasslands, fisheries,

groundwater, atmosphere, some forests

• Exploitation of the commons causes serious problems• Tragedy of the commons: ruin of the resource

• Sustainability: maintaining common-pool resources to yield benefits for present and future users


Garrett Hardin’s Tragedy of the Commons• Original commons: pastures used by anyone to graze

cattle• Whoever grazed the most cattle benefited the most• Those who reduced their cattle suffered lost profits• The commons were overgrazed

• Problems arise • With open access to a common-pool resource• But with no (or an ineffective) regulating authority• Along with no functioning community• Then profit becomes the only motive in exploiting a resource

• This tragedy can be avoided only by limiting access


Limiting freedom• Private ownership can mitigate the tragedy of the

commons• Restricts access to a renewable natural resource

• It should be exploited to guarantee continued harvest

• But this theory does not work when an owner maximizes immediate profit (e.g., corporations)

• Regulating access to a commons allows for• Protection for sustained benefits

• Fairness in access

• Mutual consent of the regulated

• Best if locally controlled by those who benefit most


Maine lobsters• Lobsters are found in Northern Hemisphere cold

marine waters• The lobster fishery is a common-pool resource

• Management of Maine’s lobster fishery involves state and local regulation• State: establishes laws protecting juveniles and

breeding females and sets the number of traps allowed

• Fishers: know and monitor each other and determine who can fish in a given area

• The state fishery is thriving, despite more fishers


Exploiting the commons


Public policies• To achieve objectives of conservation when harvesting

living resources• Consider the concepts and limitations of MSY• Consider the social and economic factors causing

overuse and degradation

• Establish and enforce protective public policies• Natural resources can be sustainably used

• Sometimes exploitation and degradation have gone too far• Restoration ecology: restoration of damaged

ecosystems


Ecosystem restoration• Restoration ecology repairs damaged lands and

waters• Returning ecosystem integrity, resilience, productivity

• A worldwide, $70 billion industry

• A thorough knowledge of ecosystem and species ecology is essential to successful restoration efforts

• Ecological problems that can be solved include• Soil erosion, strip mining, wetland draining, hurricane

damage, agricultural use, deforestation, overgrazing


Everglades restoration• Comprehensive Everglades Restoration Plan (CERP)

• Approved by Congress in 2000• Will take 36 years and $11 billion• Funded by federal and state governments, tribal and local

agencies

• Managed by the U.S. Army Corps of Engineers• Created the system that makes restoration necessary

• The Everglades has been reduced to half its size through development and wetlands draining• It holds wildlife refuges and national parks


The Everglades restoration plan


In bondage• Water in Florida slowly moves south from Lake

Okeechobee• The river of grass: 40 miles wide, 100 miles long

• Viewed as an unproductive swamp• People built levees, locks, dams, spillways• Cities and sugar croplands divert water

• Winter water shortages leave too little for natural systems• Summer rains divert too much water to the Everglades

• Agricultural runoff of nutrients (phosphorus) has degraded the water• Invasive species have overrun native vegetation


Water release• Goals of the 1996 task force to restore the

Everglades• “Getting the water right” (CERP’s role)

• Restoring, protecting, preserving habitats and species

• Promoting compatibility of natural and human systems

• The plan calls for removing levees and canals• Capturing water through reservoirs and wells

• Restoring the river of grass to a healthy system will address the second goal


Land buyout• In 2008, U.S. Sugar agreed to sell its land and

facilities to the state of Florida for $1.7 billion• 187,000 acres southeast of Lake Okeechobee

• Water stored in recreated wetlands will flow into the Everglades during the dry season

• Because of the 2008-2009 recession, this plan was scaled back to $530 million for 72,500 acres

• Future options allow the state to buy more land


Pending restorations• As values of natural ecosystems becomes

recognized, efforts to restore damaged or lost ecosystems become more important

• Large systems are the focus of restoration projects• California Bay Delta, Chesapeake Bay, Platte River

Basin, the Mississippi Delta

• Other restoration sites include the Galápagos Islands, Illinois River, Brazilian Atlantic forest, Tampa Bay


Forest ecosystems under pressure• Forests grow in areas receiving enough

precipitation for tree growth• The most productive land systems

• They perform vital natural services• Conserve biodiversity, moderate climate, prevent

erosion, store carbon and nutrients, provide recreation

• Provide goods: lumber, paper, fodder, fibers, gums, latex, fruit, berries, nuts, fuel

• The major threat: not only exploitation but total destruction


Forest resource assessments• The UN’s 2009 State of the World Forests found

that• Forests cover 30% of total land area

• Deforestation (the removal of forest and replacement by another use) continues

• The most important product is wood, and plantation forests have increased

• 9% of the world’s forests are protected and 65% have protection as a designated function

• Recognition of forest roles in climate change

• The 2010 report will use high-resolution satellite images


World forest biomes


Net changes in forest area


Forests as obstacles• Forests are obstacles to conversion to pastures

and agriculture land• Consequences of clearing a forest

• Reduced productivity, nutrients, biomass, biodiversity

• Erosion and drying of soil

• Changed hydrologic cycle

• Loss of a major carbon dioxide sink

• Loss of forest products and livelihood of people

• Countries manage forests in many different ways


Logging operations


Types of forest management• Silviculture: the practice of forest management

• For crop production (hardwood, pulp, etc.)

• Rotation: a cycle of decisions about a stand of trees • From its early growth to harvest

• Even-aged management: trees of a uniform age are managed, cut down, and then replanted• Clear-cutting: removing an entire stand at one time

• Clear-cutting creates a fragmented habitat• Impacts biodiversity and ecosystems• Efficient and does not need much management


Other management methods• Uneven-aged management: results in a more diverse

forest• Uses different harvesting strategies

• Selective cutting: some mature trees are removed• Leaves diversity and ecosystem functions

• Replanting is unnecessary

• Shelter-wood cutting: mature trees are cut in groups• Leaves some trees to provide seeds and shelter seedlings

• These methods need more management and skill but can lead to a sustainable forest


Sustainable forestry• Sustained yield: production of wood is the primary

goal• Wood is harvested without destroying the forest

• Similar to MSY: maximize harvest rates

• Ignores ecosystem properties of forests

• Sustainable forest management: managing forests as ecosystems• Maintains forest biodiversity and integrity

• Meets social, economic, cultural, and spiritual needs of present and future generations


Elements of sustainable forest management• Forest resources: reduce deforestation, restore landscapes,

maintain carbon storage, support conservation efforts• Biological diversity: conserve all levels of diversity• Forest health and vitality: protect from fire, pests, etc.• Productive functions: wood and nonwood products• Protective functions: provide valuable ecosystem services• Socioeconomic functions: cultural, spiritual, recreational• Legal, policy, and institutional framework: fair and just

use of forests; proper law enforcement


Tropical forests• Deforestation of tropical forests is of special concern

• They provide habitat for millions of species• Between 1960 and 1990, 20% was converted to other

uses• Countries need economic development

• They also have rapid population growth• The major cause of deforestation: conversion to

pastures and agriculture• Governments encourage colonization of forested lands

• Indonesia, Africa, Brazil• After slowing, deforestation rates are once again rising


Forests provide revenue• Developing countries sell logging rights to

multinational logging corporations• They harvest timber without regard to regeneration

• Chinese and other Asian companies log millions of acres in Belize, Suriname, Papua New Guinea• Weak regulations and corruption

• Millions of people live in forests or on their edges• Extracting forest goods

• There are encouraging trends in forest management in developing countries


Encouraging trends in forest management• Practicing sustainable management: 6% of tropical

forests are under a formal management plan• Designating areas for conservation: 11% of forests• Establishing plantations for wood or other

products: reduces pressure on natural forests• Setting aside extractive reserves for nontimber

uses• Preserving forests as part of a national heritage or

for tourism: can generate more money than logging• Putting forests under control of indigenous

people: to use sustainably


A plantation forest


Certification• The Forest Stewardship Council: an alliance of

nongovernmental organizations, industry, and scientists• To promote sustainable (responsible) forestry

• Certifies forest products for the consumer market

• By 2010, 110 million hectares (242 million acres) in 81 countries were certified

• Consumers can choose wood products that have been sustainably harvested


Ocean ecosystems under pressure• Oceans cover 75% of Earth’s surface

• They provide priceless goods and services

• Human activities have severely impacted these ecosystems• Commercial shipping, resource extraction, nutrient

runoff from land, fishing, species invasion, greenhouse gas emissions

• Marine fisheries provide jobs for 200 million people• Account for 15% of human protein consumption• Fishery: a limited marine area or exploited species


Human impact on ocean ecosystems


Overfishing• By the 1960s, regions of the sea were seriously

depleted• By factory ships and modern fish-finding technology

• In the mid-1970s, the Law of the Sea expanded a nation’s jurisdiction to 200 miles offshore• Established in the U.S. by the Magnuson Act of 1976

• Most fisheries fall under authority of particular nations

• Some areas recovered • But nationally based fleets increased to exploit the

fisheries


The catch• The UN’s Food and Agricultural Organization (FAO)

reports the annual harvest from fisheries and fish farms• The harvest has increased remarkably

• Aquaculture accounts for 36% of fish supplies• Accounts for the increased fish production

• “Capture” fisheries leveled off in the 1990s• 37% are species like whiting, herring, anchovy used

to feed farm-raised fish

• Salmon and shrimp aquaculture use more fish protein than they produce


The global fish harvest


The limits• The world fish catch may appear stable, but many

species and areas are overfished• 16% of fish stocks are overexploited and will decline

• 8% are depleted• One-third of the catch is used for fish meal and oil

• Aquaculture is growing in developing countries• Alleviating poverty

• Capture fisheries are at their upper limit• Restoring fisheries requires limiting/reducing fishing• Marine protected areas must be established


Georges Bank• New England’s richest fishing ground

• Cod, haddock, flounder (groundfish)• These species declined from overfishing• Increased “rough” species: dogfish (sharks), skates• Declines in these species have led to their regulation

• Prized fish species declined because of poor management• Regional management councils create management

plans• National Marine Fisheries Service (NMFS) provides

advice and information


Management councils• The New England Fishery Management Council

(NEFMC)• Set TAC quotas

• Fishermen said the TACs were too low• Were allowed to use nets that let smaller fish escape• Results were disastrous

• The NEFMC set regulations to reduce fishing pressure• Boats were restricted in days spent fishing and were

excluded from certain areas• TACs were lowered• Cod were still overfished and harvests were reduced


Fishery in distress


Other cod fisheries• The Grand Banks, off the coast of Newfoundland,

were the richest fishing grounds in the world• With government encouragement, cod were

decimated

• Closing the fishery in 1992 cost 35,000 jobs

• The cod population has not rebounded

• Europe’s North Sea cod fishery is declining• It is only 15% of what it was in the 1970s

• Fishing nations fiercely resist harvest reductions


Problems with fisheries• Too many boats, rigged with high technology, give

fish little chance of escaping• The industry has become too efficient

• Better management is needed• The size of the fleet must be reduced

• Access must be limited• Catch shares: gives fishers transferrable “property

rights”

• Fishers determine how and when they harvest

• Scientists obtain accurate population measurements


Bottom trawling


Fisheries law reauthorized• The Magnuson-Stevens Fishery Conservation and

Management Reauthorization Act (2006)• Regional councils set catch limits based on science

• Limits must be below MSY

• Use precautionary principles in setting limits

• End overfishing within two (no longer 10!) years

• Rebuild and maintain depleted stocks and limit bycatch

• Have clear accountability measures

• It does not require an ecosystem-based approach• Improves science-based approach to management


Other fisheries issues need to be addressed• Banning of shark finning for shark-fin soup• Accurate certification of “dolphin-safe” tuna• Shrimping in the Gulf of Mexico that kills

endangered sea turtles and generates huge bycatch

• Declining stocks of swordfish and tuna• Aquaculture demands placed on ocean fish

• The ground meal from ocean fish harvests is fed to pen-raised fish


Marine reserves• Marine Protected Areas (MPAs): coasts and open

oceans closed to all commercial fishing and mineral mining• Most allow small-scale fishing, tourism, recreational

boating

• Not all are rigorously managed

• Benefits: ecosystem protection, tourism, fish and larvae spill over into surrounding fisheries

• Creation of reserves is the most direct path to restoration• President G. W. Bush established three huge MPAs

surrounding the South Pacific Islands in 2009


International whaling• Whales were heavily depleted until the 1980s• The International Whaling Commission (IWC) banned

whaling any species with low populations• Immediately protected right, bowhead, and blue whales

• In 1986, a moratorium was placed on all whaling

• Japan, Iceland, Norway still whale

• Indigenous people in Alaska, the Russian Federation, and Greenland also whale

• The main threats: • Entanglement with fishing gear

• Collisions with ships


Current whaling operation


Protecting whales• Some species (bowhead, gray, and Southern right)

seem to be recovering• The ethical controversy over whaling has shifted

from conservation to animal rights• Many think it is wrong to kill such unique mammals

• Whaling nations say their cultures include eating whales—just as others eat cows or turkeys


Whale stakes• Japan, Iceland, and Norway have pressured to reopen

whaling for consumption and “scientific purposes”• Whaling minke and larger fin whales

• Japanese people are losing their taste for whale meat• It ends up in pet food or school dinners• The Japanese wrongly say whales eat too many fish

• The IWC will study whale sanctuaries and research whaling

• Australia says Japanese are whaling in their whale sanctuary• Greenpeace and the Sea Shepherd Conservation

Society harass Japanese whaling ships


Whale watching• The best hope for protecting whales is the rising

sentiment against whaling along with opportunities for whale watching

• Whale watching is an important tourist enterprise• Generating $30 million/yr in New England

• $1 billion/yr in 87 countries

• People congregate to watch whales• Whales seem to enjoy entertaining the visitors

• Whale watching provides aesthetic, entertainment, and scientific value


Whale watching


Coral reefs• Coral reefs occupy shallow coastal waters

• Atolls: islands formed by corals• One of the world’s most diverse ecosystems

• Zooxanthellae: photosynthetic algae that live in a symbiotic relationship with coral animals

• Corals build and protect land and attract tourists, fish, and shellfish

• 20% of the worlds corals have been destroyed• Temperature increases due to climate change will

bring on more coral bleaching (corals expel their algae)

• Ocean acidification from excess CO2 also kills corals


Bleached coral


Exploitation• Poverty and greed damage coral reefs

• Islanders search for fish, shellfish, etc.

• They use cyanide and dynamite to flush fish to catch for food and the pet trade• Asian countries must police reefs and retrain fishers

• Sustainable management of reefs must involve local people• Outside help may be needed

• Include coral reefs in Marine Protected Areas (MPAs)• Effective management and enforcement are vital


Mangroves• Trees inland of coral reefs growing in shallow sediments

• They protect coasts from storm damage and erosion

• Under assault from development, logging, aquaculture• Half of the world’s mangroves have been lost

• Black prawns (shrimp) are a multibillion dollar industry• Shrimp ponds become polluted, so new ponds are dug• Flushing of ponds degrades nearby habitats

• Deforestation also causes siltation of sea grasses and reefs, ruining local fisheries

• Local and international pressure for protection is increasing


Protected lands• Increasing population, industrial expansion, and

conversion of natural resources will always provide reasons to exploit ecosystems• Protection by law is the last resort for species and

ecosystems• Management is aimed at achieving specific

objectives

• These sites = 13% of Earth’s land area• Ranging from strict preserves to managed resource

use• Protected areas are not always properly managed


Public and private lands in the United States• President Obama signed the Omnibus Public

Lands Management Act (2009)• Protects 2.1 million more acres of wilderness

• Increases the wild and scenic river system by 50%

• Provides for the National Landscape Conservation System, a new federal land system

• Almost 40% of the U.S. is publicly owned• Managed by state and federal agencies for a variety

of purposes

• Most protected land is in Alaska and western states


Distribution of federal lands in the United States


Wilderness• Wilderness: land given the most protection

(preservation)• Authorized by the Wilderness Act (1964)• 109 million acres in 700 locations

• Permanently protects undeveloped and unexploited areas• Structures, roads, vehicles, logging are prohibited• Some mining and grazing may be allowed• Hiking and similar activities are allowed

• Any federally owned lands can be designated wilderness• Bureau of Land Management, National Park Service,

Forest Service, Fish and Wildlife Service


National parks and national wildlife refuges• National parks: 84 million acres

• Administered by the National Park Service

• National wildlife refuges: 96 million acres• Administered by the Fish and Wildlife Service

• Areas of great scenic or unique ecological value• Protect wildlife species

• Provide public access for recreation, etc.

• Popularity leads to parking problems and habitat destruction


Working together to manage natural sites• Agencies, environmental groups, and individuals are

working to manage natural sites as part of larger ecosystems

• The Greater Yellowstone Coalition conserves Yellowstone and Grand Teton National Parks• Plus seven national forests, three wildlife refuges, and

private land• It has addressed logging, sprawl, and road building• It has curtailed shooting of bison that leave parklands

• Cooperation is important to maintain biodiversity• Protects land outside protected areas


Greater Yellowstone ecosystem


National forests• 67% is managed for commercial timber harvest

• 75% is privately owned, mostly in the East• 25% is managed by the federal government in the

West

• Deforestation is no longer a problem in the U.S.• Second-growth forests have regenerated

• The Forest Service manages 193 million acres of national forests

• The Bureau of Land Management manages 258 million acres • Prairies, deserts, forests, mountains, wetlands, tundra


Multiple use vs. new forestry• Multiple use: the Forest Service’s old management

principle• Allowed resource extraction (grazing, logging, mining)• Also allowed recreation, watershed protection, wildlife• Intended to balance these uses, but emphasized extraction

• New forestry: the Forest Service’s new principle (late 1980s)• Protects ecological health and forest diversity• Cuts trees less frequently; leaves stream buffer zones, dead

logs, and debris; protects landscapes• Involves private landowners in management decisions• Ecosystem management is now the official paradigm


National forest timber sales


The roadless controversy• President Clinton’s Forest Service chief embraced

the ecosystem management paradigm• Roadless Area Conservation Rule: banned new

logging roads, protecting 58 million acres

• The Bush administration allowed governors to ask the Secretary of Agriculture to open land to roads and development• Resulted in conflicting court decisions

• While campaigning for president, Barack Obama promised to establish the roadless rule as law


Fires• Forest fires have become much more extensive

• Drought in western and southern states

• Higher fuel loads: dead trees and dense vegetation• Due to fire suppression and logging practices

• President Bush’s Healthy Forests Restoration Act (2003)• Allowed logging companies to thin fireprone forests• Larger trees were harvested cheaply• Restricted environmental reviews and judicial oversight

• Salvage logging harvests timber from burned forests• Increases fire risk and kills seedlings


Protecting nonfederal lands• Between 1996 and 2005, voters approved $25

billion to protect land for open space and parks• Indicates huge support for keeping open space

• Private land trust: protects land from development• A nonprofit organization accepts gifts of land• Easements: land owners give up development, but

not ownership, rights• Can also buy land to protect it

• For example, land trusts in Maine protect over 1 million acres


Final thoughts• Ecosystems everywhere are being exploited

• Wetlands, rangelands, rivers, etc.• Pressure will increase with increased human population

• In developing countries, the needs of people must be met in ways that do not destroy ecosystems• Requires wise leadership and international aid• Information on what is happening and consequences

• In 2000, UN Secretary-General Kofi Annan said, “We are plundering our children’s heritage… we need a new ethic of stewardship.”


CHAPTER 7

The Use and Restoration of Ecosystems

Active Lecture Questions


Which of the following is NOT a natural service provided by ecosystems?

a. modification of climateb. maintenance of the hydrologic cyclec. erosion control and soil buildingd. production of pollutants

Review Question-1


Which of the following is NOT a natural service provided by ecosystems?

a. modification of climateb. maintenance of the hydrologic cyclec. erosion control and soil buildingd. production of pollutants

Review Question-1 Answer


The highest possible rate of use that a system can match with its own rate of replacement or maintenance is the

a. extractive limit.b. optimum yield.c. wise-use threshold.d. maximum sustainable yield.

Review Question-2


The highest possible rate of use that a system can match with its own rate of replacement or maintenance is the

a. extractive limit.b. optimum yield.c. wise-use threshold.d. maximum sustainable yield.



The aim of conservation is to

a. preserve the environment in a pristine state.b. actively manage the environment for

optimum resource extraction.c. ensure the continuity of the system,

regardless of its potential utility.d. fragment the system for human use.

Review Question-3


The aim of conservation is to

a. preserve the environment in a pristine state.b. actively manage the environment for

optimum resource extraction.c. ensure the continuity of the system,

regardless of its potential utility.d. fragment the system for human use.



The main difference between consumptive and productive use is

a. consumptive use is applied to secondary consumers,

whereas productive is applied to producers. b. consumptive use is applied to bacteria, whereas

productive use is applied to primary consumers.c. consumptive use refers to the use of natural systems

for basic human needs, while productive use impliesuse for economic gain.

d. consumptive use refers to the value of an organismto humans, whereas productive use is based on thevalue of the organism in and of itself.

Review Question-4


The main difference between consumptive and productive use is

a. consumptive use is applied to secondary consumers,

whereas productive is applied to producers. b. consumptive use is applied to bacteria, whereas

productive use is applied to primary consumers.c. consumptive use refers to the use of natural

systems for basic human needs, while productive

use implies use for economic gain.d. consumptive use refers to the value of an organism

to humans, whereas productive use is based on thevalue of the organism in and of itself.



___________ refers to the problems that arise when the exploitation of common pool resources causes the eventual ruin of the resource.

a. Shakespearean tragedyb. Conservation poolingc. Tragedy of the commonsd. Restoration pooling

Review Question-5


___________ refers to the problems that arise when the exploitation of common pool resources causes the eventual ruin of the resource.

a. Shakespearean tragedyb. Conservation poolingc. Tragedy of the commonsd. Restoration pooling



According to Fig. 7-6, when a population is at carrying capacity,

a. yield is reduced by competition.

b. maximum sustainable yield is possible.

c. yield is reduced by decreased population sizes.

d. recruitment is low.

Interpreting Graphs and Data-1


According to Fig. 7-6, when a population is at carrying capacity,

a. yield is reduced by competition.

b. maximum sustainable yield is possible.

c. yield is reduced by decreased population sizes.

d. recruitment is low.

Interpreting Graphs and Data-1 Answer


According to Fig. 7-14, between 1960 and 2006 the world’s total fish harvest was

a. in decline year after year.

b. increasing year after year.

c. staying approximately the same.

d. fluctuating dramatically.

Interpreting Graphs and Data-2


According to Fig. 7-14, between 1960 and 2006 the world’s total fish harvest was

a. in decline year after year.

b. increasing year after year.

c. staying approximately the same.

d. fluctuating dramatically.

Interpreting Graphs and Data-2 Answer


Which of the following is the current major cause of deforestation of the tropics?

a. conversion to pastures and agricultureb. conversion to municipalitiesc. restoration of plantationsd. all of the above

Thinking Environmentally-1


Which of the following is the current major cause of deforestation of the tropics?

a. conversion to pastures and agricultureb. conversion to municipalitiesc. restoration of plantationsd. all of the above

Thinking Environmentally-1 Answer


Fishers are currently prohibited from hunting large whales under the __________ Act.

a. Marine Reservesb. Endangered Species c. Magnuson-Stevens Fishery Conservation

and Management Reauthorizationd. Wild Species Restoration

Thinking Environmentally-2


Fishers are currently prohibited from hunting large whales under the __________ Act.

a. Marine Reservesb. Endangered Species c. Magnuson-Stevens Fishery Conservation

and Management Reauthorizationd. Wild Species Restoration

Thinking Environmentally-2 Answer

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© 2011 Pearson Education, Inc. CHAPTER 7 The Use and Restoration of Ecosystems